Hydraulic valve lifter



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F. J. GoNcALvEs HYDRAULIC VALVE LIFTER Filed Oct. 6, 1961 ile n 7.

Oct. 16, 1962 s. J, v w Mm 7 m? G d WM N l f W United States Patent @moe 3,058,454 Patented Oct. 16, 1962 3,058,454 HYDRAULIC VALVE LIFTER Francis J. Goncalves, 506 Locust Ave., Centralia, Pa. Filed Oct. 6, 1961, Ser. No. 143,455 1 Claim. (Cl. 12S- 90) This invention relates to improvements in hydraulic valve lifters, and more particularly to a valve lifting assembly adapted to be employed for transmitting lifting action between the cam and the push rod of a valve in an internal combustion engine.

A main object of the invention is to provide a novel and improved hydraulic valve lifter which is relatively simple in construction, which is quiet in operation, which will not stick, and which is not subject to excessive wear.

A further object of the invention is to provide an improved hydraulic valve lifting assembly adapted to be employed between a valve cam and the push rod of the valve of an internal combustion engine, the valve lifting assembly being provided with improved means for lubrieating same so that it will be smooth in operation and will operate reliably over a long period of time without requiring servicing or replacement.

Further, objects and advantages of the invention will become yapparent from the following description and claims, and from the accompanying drawings, wherein:

FIGURE l is a perspective view, partly in cross section, of an improved hydraulic valve lifter constructed in accordance with the present invention.

FIGURE 2 is a perspective view of the abutment head employed in the valve lifter assembly of FIGURE l.

FIGURE 3 is a perspective view of the plunger element employed in the valve lifter assembly of FIGURE l.

FIGURE 4 is an enlarged fragmentary developed elevational view of a portion of the exterior surface of the plunger element of FIGURE 3.

FIGURE 5 is an enlarged vertical cross sectional view taken substantially on the line 5--5 of FIGURE 3.

FIGURE 6 is a horizontal cross sectional view taken substantially on the line 6-6 of FIGURE 5.

Referring to the drawings, 11 generally designates an improved valve lifter assembly constructed in accordance with the present invention. The assembly 11 comprises a generally cylindrical tappet 12 of hollow construction which is provided in its lower portion with an oil chamber 13, the upper portion of the tappet 12 being provided with a substantially smooth inner bore 14. Designated at 15 is a generally cylindrical hollow plunger which is slidably mounted in said inner bore, said plunger being provided at its lower end with conventional check valve means 16 to allow oil to pass downwardly therethrough into the oil chamber 13. Seated on the top end of the plunger 15 is an abutment head 17 which comprises a generally cylindrical main body portion 18 having a tapered Ibottom end 19, said body portion being provided with `an annular supporting ange 20 at its top end which is substantially ilush with the exterior surface of the generally cylindrical plunger 15. The top of the abutment head 17 is formed with a spherical recess 21 adapted to receive the rounded bottom end of a valve push rod, not shown, for transmitting upward force to said push rod. The bottom end 22 of the tappet 12 is adapted to engage on a valve cam in a conventional manner for regulating the opening of the associated valve.

A coiled spring 23 is mounted in the oil chamber 13 and bears upwardly on the plunger element 15 to resiliently transmit upward force to the plunger element, and to automatically take up wear between the rounded bottom end of the push rod and the abutment head =17.

The tappet and the plunger are formed with registrable openings 24 and 25 for allowing oil to pass from the exterior of the tappet into the interior cavity 27 of the plunger, the oil traveling downwardly through the bottom check valve 16 Iin the plunger towards the oil chamber 13. The oil is delivered in a conventional manner to the openings 25 of the tappet from the oil gallery of the associated internal combustion engine in a manner well known to those skilled in the art.

In the `devices of the prior art, no specific means is provided for allowing'passage of oil downwardly between the external surface of the plunger and the inside surface of the tappet, so that in many instances the plunger tends to bind in the tappet, resulting in noisy operation and excessive wear of the interengaging surfaces of these elements. In accordance with the present invention, the exterior surface of the plunger is formed with intersecting diagonal grooves distributed thereover to allow distribution of oil through the grooves, whereby to lubricate the inner bore of the tappet. Thus, the plunger is formed with an annular main groove 28 whichextends around the periphery of the plunger and which communicates directly with the oil holes 24 therein, as is clearly shown in FIGURE 3. The exterior surface of the plunger is diamond-knurled above and below the peripheral groove 28, as shown respectively at 29 and 30 to define the intersecting diagonal grooves 31 above mentioned, the grooves being distributed over the entire external surface of the plunger above and below the peripheral groove 28, as illustrated in FIGURE 3.

A-s -shown in FIGURE 2, the external surface of the main depending portion of the abutment head 17 is 'similarly diamond grooved, as shown at 33, to provide intersecting diagonal grooves over its entire surface to allow lubrication of the adjacent inside bore surface of the hollow plunger.

As will be readily apparent, when `the oil flows through the oil holes 25 in 'the tappet 12, the oil is rst in communication with the annular groove 28 in the plunger and thus is admitted freely into .the intersecting diagonal grooves 31 whereby the oil is distributed over the entire inside surface of the tappet 12, providing complete and eflicient lubrication thereof. This Iallows free movement of the plunger 15 longitudinally in the bore of the tappet at all times and allows the spring 23 to act efficiently to take up any wear which may occur between the rounded bottom end of the push rod and the spherical socket 21 of the abutment head 17, and also allows the spring to serve as a cushioning means to allow the plunger to reciprocate in the bore of the tappet 12 with a minimum of friction.

In the same manner, the exterior surface of the depending main body portion 18 of the vabutment head 17 provides free distribution of oil on the adjacent inside surface of the hollow plunger 15, so that the abutment head 17 is free to adju-st itself at all times to provide centering thereof in the plunger and to Iassure even bearing action between the flange 20 thereof and the top rim of the plunger.

While a specific embodiment of an improved hydraulic valve lifter assembly has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, Vit is intended that no limitations be placed on the invention except as delined by the scope of the appended claim.

What is claimed is:

A hydraulic valve lifter comprising a generally cylindrical tappet having an oil chamber -in its lower portion, said tappet having a smooth inner bore, a hollow plunger slidably mounted in said inner bore, check valve means in the lower end of the plunger to allow oil to pass downwardly therethrough, an abutment head movably engaged in said plunger and being engageable by the lower end of a valve push rod, said abutment head being provided with an vannular ysupporting flange substantially flush with the exterior surface of the plunger, and a coiledspring in said oil chamber supportingly engaging said plunger, said tappet and plunger being formed with registrable oil holes, and the exterior surfaces of the plunger and the main body portion of the abutment head being diamondknurled over Itheir entire areas to deiine intersecting diagonal grooves distributed thereover to allow distribution of oil through said grooves over the surfaces adjacent thereto, whereby to lubricate `said l.abutment head to maintain -it free -to kadjust itself to centered position on said plunger, the exterior surface of the plunger being References Cited in the file of this patent UNITED STATES PATENTS 2,827,887 Van Slooten Mar. 25, 1958 1,951,959 Alexandrescu Mar. 20, 1934 2,676,579 Gerner Apr. 27, 1954 1,877,530 Read Sept. 13, 1932 

